Early recurrence detected by 18F-FDG PET/CT in patients with resected pancreatic ductal adenocarcinoma

18F-FDG-PET/CT Imaging for Gastrointestinal Malignancies

Gastrointestinal malignancies encompass a variety of primary tumor sites, each with different staging criteria and treatment approaches. In this review we discuss technical aspects of 18F-FDG-PET/CT scanning to optimize information from both the PET and computed tomography components. Specific applications for 18F-FDG-PET/CT are summarized for initial staging and follow-up of the major disease sites, including esophagus, stomach, hepatobiliary system, pancreas, colon, rectum, and anus.

Predicting early recurrence for resected pancreatic ductal adenocarcinoma: a multicenter retrospective study in China

A precise classification of early recurrence (ER) after radical surgery of pancreatic ductal adenocarcinoma (PDAC) has not been standardized. We aim to develop an optimal cut-off based on scientific evidence to distinguish early and late recurrence (LR) for PDAC after radical surgery and develop a predictive model for ER of PDAC. The best threshold for recurrence-free survival (RFS) was assessed with a minimum P-value method, and patients were categorized into ER and LR groups. We used a logistic regression model to assess potential risk factors for ER and develop a predictive model for ER risk. The best threshold between high-risk and intermediate-high-risk groups was identified by using the receiver operating characteristic curve. Among 3,279 patients included, 1,234 (37.6%) experienced ER. The RFS of 9 months is the optimal threshold to distinguish ER and LR. Univariable and multivariable analysis identified four preoperative risk factors for ER, including larger tumor maximal diameter on computed tomography (CT), enlarged lymph nodes on CT, carbohydrate antigen (CA) 125 > 35 U/ml, and CA19-9 > 235 U/ml. The concordance index (C-index) for the predictive model in the training cohort and the validation cohort was 0.651 (95% confidence interval (CI): 0.624-0.678), and 0.636 (95% CI: 0.593-0.679), respectively, showing promising predictive ability. The high-risk group had a score above 203, and the corresponding risk of ER for this group was 56.7%. An RFS of 9 months is the best threshold to distinguish ER and LR. The model can accurately predict the risk of ER in PDAC after radical resection, and risk grouping can predict the patients who could benefit from upfront surgery.

Pancreatic Ductal Adenocarcinoma: The Dawn of the Era of Nuclear Medicine?

Pancreatic ductal adenocarcinoma (PDAC), accounting for 90-95% of all pancreatic tumors, is a highly devastating disease associated with poor prognosis. The lack of accurate diagnostic tests and failure of conventional therapies contribute to this pejorative issue. Over the last decade, the advent of theranostics in nuclear medicine has opened great opportunities for the diagnosis and treatment of several solid tumors. Several radiotracers dedicated to PDAC imaging or internal vectorized radiotherapy have been developed and some of them are currently under clinical consideration. The functional information provided by Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) could indeed provide an additive diagnostic value and thus help in the selection of patients for targeted therapies. Moreover, the therapeutic potential of β-- and α-emitter-radiolabeled agents could also overcome the resistance to conventional therapies. This review summarizes the current knowledge concerning the recent developments in the nuclear medicine field for the management of PDAC patients.

Overlooked risk for needle tract seeding following endoscopic ultrasound-guided minimally invasive tissue acquisition

Endoscopic ultrasound-guided minimally invasive tissue acquisition can be performed by two approaches as follows: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB). These have been evolved into leading approaches and widely used for the histological diagnosis of tumors in the gastrointestinal tract and adjacent organs. However, the role of EUS-FNA and EUS-FNB in disease diagnosis and evaluation remains controversial. Although the incidence of surgery-associated complications remains low, the consequences of needle tract seeding can be serious or even life-threatening. Recently, increasing case reports of needle tract seeding are emerging, especially caused by EUS-FNA. This complication needs serious consideration. In the present work, we integrated these case reports and the related literature, and summarized the relevant cases and technical characteristics of needle tract seeding caused by EUS-FNA and EUS-FNB. Collectively, our findings provided valuable insights into the prevention and reduction of such serious complication.

Prognostic Implications of 18-FDG Positron Emission Tomography/Computed Tomography in Resectable Pancreatic Cancer

There are currently no known preoperative factors for determining the prognosis in pancreatic cancer. The aim of this study was to examine the role of 18-fluorodeoxyglucose (18-FDG) positron emission tomography/computed tomography (18-FDG-PET/CT) as a prognostic factor for patients with resectable pancreatic cancer. Data were obtained from a retrospective analysis of patients who had a preoperative PET scan and then underwent pancreatic resection from January 2007 to December 2015. The maximum standardized uptake value (SUVmax) of 18-FDG-PET/CT was calculated. Patients were divided into high (>3.65) and low (≤3.65) SUVmax groups, and compared in terms of their TNM classification (Union for International Cancer Contro classification), pathological grade, surgical treatment, state of resection margins, lymph node involvement, age, sex, diabetes and serum Carbohydrate Antigen 19-9 (CA 19-9) levels. The study involved 144 patients, 82 with high SUVmax pancreatic cancer and 62 with low SUVmax disease. The two groups’ disease-free and overall survival rates were significantly influenced by tumor stage, lymph node involvement, pathological grade, resection margins and SUVmax. Patients with an SUVmax ≤ 3.65 had a significantly better survival than those with SUVmax > 3.65 (p < 0.001). The same variables were independent predictors of survival on multivariate analysis. The SUVmax calculated with 18-FDG-PET/CT is an important prognostic factor for patients with pancreatic cancer, and may be useful in decisions concerning patients’ therapeutic management.